Manufacture of artificial hemp fiber.



rirnn s ra'rns Parana orrroa.

FRIEDRICH LEHNER, OF

ZURICH, SWITZERLAND.

MANUFACTURE OF ARTEFBCBAL HEMP FEBER.

- Specification of Letters Patent.

,Patented. May 7, 1907.

"' Application filed May 16, 1906. Serial No. 317,240.

enable others skilled in the art to which it apertains to make and use the same.

This invention relates to an improved method of manufacturing artificial hemp fiber having for its object the provision of a substitute material which, while possessing the characteristic appearance and advantages of the natural product, is withoutthe disadvantages accompanying the same.

Natural unhackled hemp fiber freed from woody matter and in lengths of about a half meter, finds extensive employment in the industries and especially in the manufacture of hats. This material is inconvenient inuse, however, by reason of the difficulties encountered'in working the same, due to the troublesome knitting togetherwf the single strands in producing small threads or ribbons as a work material' The strands or filaments manifest a very undesirable lack of'uniformity in thickness and breadth, due in part to thepreparation of the same from the plant and, moreover, the many irregularities and knots are troublesome obstacles to the satisfactory working of the same in the arts. hemp fiber has a characteristic dull luster which is liked in the .art and which is not possessed. by the substitutes which have been proposed hitherto.

By this invention it is proposed to produce an article possessing every appearance of the natural hem fiber without its disadvantages, and avai able .for use in unlimited lengths and of a uniform thickness and width. It has already been proposed to form textile work material by gluing together, according to the size re ulred, of one or more filaments or strands ying parallel to each other. A thread so formed,however, corresponds in appearance to the material from which it is made. A thread made from silk, for instance, shows a characteristic natural silk gloss", artificial silk has a more highly lustrous strawy appearance, and that formed from bleached cotton shows the duller white tone of the raw material; None of these materials have been made to show the characteristic dull gloss and peculiar color of the hemp fiber, nor do they possess its capacity for dyes.

By the improvedprocess herein set out, lustrousthreadsof silk, artificial silk, mercerized cotton and the like, either singly or in combination with ,two or more similar threads, are subjected to a process by which their luster is dulled, by the same means or at the same time that they are glued together to form a thread or ribbon, corresponding to that of the hemp fibers desired to be produced. a

According to this process, one or more lustrous filaments of. natural silk, artificial silk, viscose silk, mercerized cotton and the like, are subjected to a bath in a suitable binding material insoluble in water, such, for instance, as collodion, dissolved cellulose or viscose. After removing the surplus bind- "ing material, that remaining is fixed in a known manner by drying or by decomposition', as by subjecting to an acid, whereupon the thread 'or ribbon so obtained is wound upon a reel or spool for future use.

For the purpose of dulling the luster of the material to correspond to that which it is to simulate, to the binding material, either before, during, or after the manufacture of the ribbon, a suitable luster-dulling coating substance is added, such, for instance, as heavy spar, pulverized chalk, zinc white, amorphous sulfur and the like, and also an appro- On the other hand, the natural priate dye toproduce the yellowish shade characteristic of the hemp fiber. It is also possible, however, to produce this coating or luster-modifying efiect by a chemical treatment of the binding material itself, either by a separate rocess or simultaneously with the fixing of t e same, as, for.instance, where a watery viscose solution is 'used, the treated ribbon or thread,,before the binding material has become fixed, can be drawn through, or otherwisesubjected to a mineral acid, by which treatment sulfur is. separated out. This separated 'amor houssulfur suffices for the coating and dulllng of the thread or ribbon so that a further addition of coating mataining a coating material adapted to dull I the luster of the product.

- 2. The process of producing artificial hemp fiber which consists in gluingtogether a plurality of lustrous filaments and modifying the luster of the same to approximate that of hemp fiber. L

' 3. The process of producing artificial hemp fiber which consists in gluing together a plurality of lustrous filaments bya viscose solution, and subjecting the freshly treated fibers to a mineral acid, whereby the binding material is fixed and the luster of the product is dulled.

of a mineral acid, whereby the binding material is 'fixed and the amorphous sulfur is separated out to dull the luster of the product.

In testimony whereof I hereunto aflix my signature in the presence of tWo Witnesses.

FRIED-RICH LEHNER.

Witnesses:

A. LIEBERKNECHT,

WALKER RAsoHERT.

. 4. The process of producing artificial hemp fiber which consists in gluing. together a plurality of lustrous filaments by a viscose soluv, tion containing a suitable dye, and subjecting the freshly treated filaments to. the action 

